A specific member of the ATF transcription factor family can mediate transcription activation by the adenovirus E1a protein.

The adenovirus E1a protein stimulates transcription of viral early genes. Recent experiments indicate that E1a contains a transcriptional activating region, which functions when directed to a promoter. Because E1a is not a sequence-specific DNA binding protein, how it targets to viral promoters has been a question. Several of the viral early promoters contain one or more binding sites for ATFs, a family of cellular transcription factors. Here we show that E1a can function through a specific ATF protein, designated ATF-2. We provide evidence that E1a interacts with a discrete region of promoter-bound ATF-2, thereby positioning the E1a activating region at a viral promoter.